Went random twice and pretty much went 0/2. The first go around was a 4-person room, so me and 3 other guys. I got along with one of them, indifferent towards another, and couldn't stand the 3rd one. I switched schools at semester and could've joined my cousins at ISU who were both my age and getting an apartment together, but for reasons I can't remember, chose to move back home and commute to NIACC. Go Trojans! Part 2 of random experience was at UNI where I joined up in the dorms with a dude who seemed nice enough, but I inevitably withdrew and moved back home after a couple weeks. I'm not sure it had anything to do with him. I was a little love stricken at the time and my head wasn't right. The randomness of my situation didn't make sense and was making me really uneasy about life. I had left a girl that I thought I loved at home, where I also still had friends and a decent full time job.
Took a year off from school and broke up with the girl. Went back to UNI but this time made sure I knew who my roommates were. I was done messing around after two not so great experiences and really just wanted to increase my odds for academic success, which to me meant not having anxiety about not knowing the people I lived with. Met friends through work, classes, student orgs etc. as others have noted. I'd probably do it the same way again if I had to. To me, it is 100% dependent on the personality of the individual whether the random method will work or not. Sometimes you just can't force a square peg into a round hole.